Captive fasteners with multiple retaining functionality

ABSTRACT

Captive panel fasteners are configured to be held captive on a panel by multiple retaining elements. The fasteners include longitudinal grooves along a cylindrical portion of the fastener, a retaining ring over the cylindrical portion, a primary structure for retaining the retaining ring on the cylindrical portion, and secondary structure for retaining the cylindrical portion within a bore of the panel. The retaining ring includes radially inwardly extending opposing prongs that fit into the longitudinally extending grooves. A stop point may be provided in the longitudinally extending grooves, or an end of the fastener may be flared, to retain the retaining ring on the fastener. The prongs may also be slightly flexible and flared to grip the longitudinally extending grooves. The secondary structure can include one or more spring loaded pins in the fastener extending externally outward.

CROSS-REFERENCES TO RELATED APPLICATIONS

This application is a division of application Ser. No. 12/852,418, filedAug. 6, 2010, which is based upon and claims domestic priority from U.S.provisional Application No. 61/232,379, filed Aug. 7, 2009; U.S.provisional Application No. 61/303,265, filed Feb, 10, 2010; and U.S.provisional Application No. 61/362,256, filed Jul. 7, 2010; each ofwhich is incorporated by reference herein.

BACKGROUND OF THE INVENTION

The present invention relates generally to captive panel fasteners, andmore particularly relates to a captive panel fastener that can be heldcaptive on a panel by multiple retaining elements integral with thefastener itself or associated with the fastener, prior to securing of anut or other panel by the fastener.

Captive panel fasteners are used in the aerospace industry to holdaircraft panels in place. Captive panel fasteners are arranged so that ascrew is held in position extending through an opening in a panel, withthe threaded end of the screw extending out through the other side ofthe panel. In the aerospace industry, it is important that thesefasteners be held properly in position, with the fastener held captiveon the panel ready for the securing of the threaded end into a nut orhole. What is needed is an improved captive panel fastener design thatprevents such fasteners from recessing into or out of a panel. Thepresent invention meets this and other needs.

SUMMARY OF THE INVENTION

Briefly and in general terms, the present invention provides forimproved designs for captive panel fasteners configured to be heldcaptive on a panel by multiple retaining elements integral with thefastener itself or associated with the fastener.

Accordingly, the present invention provides for a captive panel fastenerassembly with multiple retaining elements to be installed in a bore of apanel, including a fastener including a cylindrical member, a pluralityof longitudinally extending grooves defined along an external surface ofthe cylindrical member extending between the first end portion and thesecond end portion of the cylindrical member, a retaining ring mountedover the cylindrical member, primary means for retaining the retainingring on the cylindrical member, and secondary means for retaining thecylindrical member within the bore of the panel. In a presentlypreferred aspect, the retaining ring includes at least two radiallyinwardly extending opposing prongs that fit into the plurality oflongitudinally extending grooves of the cylindrical member, wherein theplurality of longitudinally extending grooves include radially innersurfaces separated by a first distance, and the inwardly extendingopposing prongs are separated by a second distance that is less than thefirst distance between the radially inner surfaces of the plurality oflongitudinally extending grooves.

In one presently preferred aspect, the primary means for retaining theretaining ring on the cylindrical member includes a stop point definedin the longitudinally extending grooves at or near an extreme end of thesecond end portion of the cylindrical member. In another presentlypreferred aspect, the primary means for retaining the retaining ring onthe cylindrical member includes the second end portion of thecylindrical member being flared to form a flared portion of the secondend portion of the cylindrical member, so that the flared portion of thesecond end portion of the cylindrical member has an outer diameter thatis larger than the second distance separating the inwardly extendingopposing prongs of the retaining ring, to retain the retaining ring onthe cylindrical member. In another presently preferred aspect, theretaining ring includes a main body formed in a plane, and the at leasttwo radially inwardly extending opposing prongs are connected to themain body and extend radially inwardly from the main body in the plane.

In another presently preferred aspect, the primary means for retainingthe retaining ring on the cylindrical member includes the at least tworadially inwardly extending opposing prongs being slightly flexible andflared, and the at least two radially inwardly extending opposing prongsare biased to grip the plurality of longitudinally extending grooves andresist movement of the retaining ring along the plurality oflongitudinally extending grooves along the cylindrical member.

In a presently preferred aspect, the secondary means for retaining thecylindrical member within the bore of the panel includes at least onespring loaded pin positioned internally within the cylindrical membernear the second end portion of the cylindrical member, the at least onespring loaded pin extending externally through the cylindrical member.In another aspect, the at least one spring loaded pin includes aplurality of spring loaded pins.

In another presently preferred aspect, the retaining ring includes atubular retaining sleeve including a first portion and a second portion,the first portion having a first radially outer diameter, and the secondportion having a second radially outer diameter smaller than the firstradially outer diameter of the first portion of the retaining sleeve,and the secondary means for retaining the cylindrical member within thebore of the panel includes the first radially outer diameter of thefirst portion of the retaining sleeve being larger than an innerdiameter of the panel hole, and the second radially outer diameter ofthe second portion of the retaining sleeve being smaller than the innerdiameter of the panel hole. The retaining sleeve includes a lumentherethrough with an inner diameter larger than the outer diameter ofthe cylindrical member, and the retaining sleeve is fitted over thecylindrical member with the first end portion of the retaining sleeve ona first side of the panel, with the prongs positioned in correspondingones of the plurality of longitudinally extending grooves of thecylindrical member, and the second portion of the retaining sleeve isflared on a second side of the panel. In another presently preferredaspect, the bore of the panel has a conical shape, and the secondportion of the retaining sleeve is flared to have a correspondingconical shape. In another presently preferred aspect, a washer ismounted in the bore of the panel adjacent to the flared portion of thesecond end portion of the cylindrical member, such as by an adhesive. Inanother presently preferred aspect, the bore of the panel has a conicalshape and the washer has a corresponding conical shape.

In another presently preferred aspect, the present invention alsoprovides for a method for installing a captive panel fastener withmultiple retaining elements in a bore of a panel. The captive panelfastener includes a cylindrical member with one or more spring loadedpins positioned internally within the cylindrical member and extendingexternally through the cylindrical member near an end portion of thecylindrical member opposite a head of the captive panel fastener. Aretaining ring including at least two radially inwardly extending,slightly flexible, flared opposing prongs is mounted over thecylindrical member with the prongs fitting into correspondinglongitudinally extending grooves of the cylindrical member, so that theprongs of the retaining ring grip the cylindrical member and resistmovement of the retaining ring along the longitudinally extendinggrooves along the cylindrical member. The one or more spring loaded pinsare positioned within a bore of the panel to depress the one or morespring loaded pins within the bore of the panel, to thereby hold thecaptive panel fastener within the bore of the panel, and the retainingring is positioned on a side of the panel to prevent the captive panelfastener from coming out of the bore of the panel.

In another presently preferred aspect, the present invention alsoprovides for a method for installing a captive panel fastener withmultiple retaining elements in a bore of a panel, including the steps ofproviding a panel including a bore therethrough, and providing a captivepanel fastener including a cylindrical member. The cylindrical memberincludes a first end portion, a second end portion located opposite thefirst end portion, an externally threaded portion between the first endportion and the second end portion, and at least one spring loaded pinpositioned internally within the cylindrical member near the second endportion of the cylindrical member, and extending externally through thecylindrical member. A plurality of longitudinally extending grooves aredefined along an external surface of the cylindrical member extendingbetween the first end portion and the second end portion of thecylindrical member, although the longitudinally extending grooves do notextend all the way to an extreme end of the second end or bottom endportion of the cylindrical member, but instead stop at a stop pointbefore reaching the extreme end of the second end or bottom end portionof the cylindrical member. A retaining ring including at least tworadially inwardly extending opposing prongs that fit into the pluralityof longitudinally extending grooves of the cylindrical member is mountedover the cylindrical member, using an installation tool a tool endportion having a beveled portion on one side of the tool end portion anda slot on an opposing side of the tool end portion. The captive panelfastener is inserted into the bore of the panel, a first one of theprongs of the retaining ring is inserted into a first one of theplurality of longitudinally extending grooves, and the installation toolis positioned such that a second one of the prongs of the retaining ringis disposed inside the slot of the installation tool. The retaining ringis then pulled with the installation tool so that the second of theprongs are inserted into a second of the longitudinally extendinggrooves. The captive panel fastener is pulled through the bore of thepanel, while positioning the at least one spring loaded pin near thesecond end portion of the cylindrical member within the bore of thepanel to depress the at least one spring loaded pin within the bore ofthe panel, to thereby hold the captive panel fastener within the bore ofthe panel, and the retaining ring is positioned on a side of the panelto prevent the captive panel fastener from out of the bore of the panel.

These and other features and advantages of the present invention willbecome more apparent from the following detailed description of thepreferred embodiments in conjunction with the accompanying drawings,which illustrate, by way of example, the operation of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a cross sectional view through a conical washer and panel forpreparation of the captive panel fastener assembly according to theinvention.

FIG. 2 is an exploded view of the captive panel fastener assembly,showing a screw type fastener, retaining sleeve and a partial sectionalview of a panel with a washer glued onto the panel according to theinvention.

FIG. 3A is an elevational view of the sleeve of the captive panelfastener assembly of FIG. 2.

FIG. 3B is a cross-sectional view of the sleeve of the captive panelfastener assembly of FIG. 2.

FIG. 4 is a plan view of the sleeve of FIG. 3A.

FIG. 5 is a partial cross-sectional view through a screw type fastenerand retaining sleeve installed into a panel according to the invention.

FIG. 6 is a partial cross-sectional view illustrating the flaredretaining sleeve according to the invention.

FIG. 7 is a partial cross-sectional view illustrating the flared end ofthe screw type fastener according to the invention.

FIG. 8 is another partial cross-sectional view illustrating the flaredend of the screw type fastener to the invention.

FIG. 9 is a top view of a screw type fastener according to theinvention.

FIG. 10 is a top view of the fastener according to the invention.

FIG. 11 is a side view of a fastener according to the invention.

FIG. 12 is a cross sectional view of the fastener through the line12-12, according to the invention.

FIG. 13 is a side view of the fastener installed into a panel accordingto an embodiment of the invention.

FIG. 14 is a plan view of a retaining ring with inwardly extendingprongs according to the invention.

FIG. 15 is a side view of the retaining ring according to the invention.

FIG. 16 illustrates a tool for use with installing a retaining ring ontoa captive fastener according to the invention.

FIG. 17 illustrates one prong of a retaining ring installed into thegroove of a captive fastener according to the invention.

FIG. 18 illustrates a tool inserting the second prong of a retainingring onto a captive fastener according to the invention.

FIG. 19 illustrates a cross sectional view of a portion of the captivefastener in which a spring-loaded pin is fully extended.

FIG. 20 is a cross sectional view of a portion of the captive fastenerin which a spring-loaded pin is depressed.

FIG. 21 is a top view of the fastener according to the invention.

FIG. 22 is a side view of a fastener of FIG. 21, according to theinvention.

FIG. 23 is a cross sectional view of the fastener through the line 23-23of FIG. 22, according to the invention.

FIG. 24 is a side view of the fastener of FIG. 21 with a retaining ringmounted on the fastener, showing the fastener installed into a panel.

FIG. 25 is a plan view of the retaining ring with radially inwardlyextending prongs of FIG. 24.

FIG. 26 is a side view of the retaining ring of FIG. 25.

FIG. 27 is a top plan view of the fastener of FIG. 21.

FIG. 28 is a cross-sectional view taken along line 28-28 of FIG. 27.

FIG. 29 is a cross-sectional view taken along line 29-29 of FIG. 27.

FIG. 30 is a detail view of a portion of FIG. 27.

FIG. 31 is an enlarged plan view of the retaining ring of FIG. 25,illustrating the formation of the radially inwardly extending, slightlyflexible, flared opposing prongs of the retaining ring according to theinvention.

FIG. 32 is a partial sectional view of the retaining ring, taken alongline 32-32 of FIG. 21.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Referring to the drawings, which are provided by way of example, and notby way of limitation, and in which like elements are identified withlike reference numbers, in a first presently preferred embodiment, theinvention provides for a captive panel fastener assembly 40 withmultiple retaining elements including a captive panel fastener 42, suchas a screw or bolt, for example. The captive panel fastener typicallyincludes a head 44 attached to a cylindrical member or shank 46. Thecylindrical member has an unthreaded first end or top end portion 48which connects to the head, a second end or bottom end portion 50, whichis located opposite the first end or top end portion, and an externallythreaded portion 52 between the unthreaded first end or top end portionand the second end or bottom end portion.

As is illustrated in FIG. 2, a plurality of longitudinally extendinggrooves or slots 56, such as two longitudinally extending grooves orslots, for example, run along the cylindrical member between the firstend or top end portion and the second end or bottom end portion. Thelongitudinally extending grooves or slots may have a recess depth ofapproximately 0.055 to 0.045 inches in a cylindrical member having anouter diameter of approximately 0.2459 to 0.2490 inches, for example.The head of the captive panel fastener may include any type of drivingarrangement 62, such as a conventional slot, a Phillips, or Allen headrecess, or the like. FIG. 9 illustrates a top view of the head in theshape of a hexagon having a six-lobe recess 64. A top view of the headof the captive panel fastener is shown in FIG. 9. In the embodiment ofthe invention shown, the head of the screw includes a six-lobed recesscompatible with a mating tool to allow torqueing of the screw. However,those skilled in the art will understand that a head of any shape andrecessed configuration may be provided.

The captive panel fastener assembly also includes a retaining sleeve 66,illustrated shown in FIGS. 3A, 3B and 4. The retaining sleeve includesat least two radially inwardly extending opposing prongs 68 that fitinto the longitudinally extending grooves of the cylindrical member ofthe fastener. The opposing prongs are formed to extend in the same planeas the main body 69 of the retaining ring, and the opposing prongs areseparated by a first distance A shown in FIG. 4 that is slightly lessthan the distance B between the radially inner surfaces, floors orbottoms 70 of the plurality of longitudinally extending grooves or slotsalong the cylindrical member.

FIGS. 2-8 illustrate installation of a retaining sleeve onto a captivepanel fastener for installation of the captive panel fastener assemblyinto a panel 72, including a hole or bore 74 for inserting the captivepanel fastener of the invention, or another fastener, such as a screw orbolt, for example.

As is illustrated in FIG. 1, a washer 76 may be installed into the holeof a panel by an adhesive or glue, such as Permabond Super Glue orLoctite Super Bonder for example. Alternately, the washer may beinstalled using other adhesives known to those skilled in the art. Inone embodiment, the washer can be a conical-shaped washer, and the holeof the pane has a corresponding conical shape for receiving the washer.Those skilled in the art will appreciate that other shaped washers maybe used and installed onto the panel. Once the washer is installed ontothe panel, the sleeve and screw assembly may then be installed in thepanel, with the washer affixed to the hole of the panel, as isillustrated in FIG. 2.

The retaining sleeve includes a first portion 78 with a first radiallyouter diameter 80, and a second portion 82 with a second radially outerdiameter 83 smaller than the first radially outer diameter. The firstradially outer diameter is preferably larger than the inner diameter 84of the panel hole, and the second radially outer diameter is preferablysmaller than the inner diameter of the panel hole. The retaining sleeveincludes a lumen 86 therethrough with an inner diameter 88 larger thanan outer diameter 90 of the cylindrical shank of the fastener, so thatthe sleeve can be fitted over the cylindrical shank of the fastener. Theretaining sleeve is mounted over the end of the captive panel fastenerwith the prongs positioned in the corresponding grooves or slots of thecylindrical member. The threads of the screw may be rolled onto theshank of the screw with the sleeve in place. As is illustrated in FIG.2, the screw and sleeve are installed into the panel resulting in theassembly illustrated in FIG. 5.

When the retaining sleeve is installed over the captive panel fastenerand in the panel hole, as illustrated in FIGS. 5 and 6, the secondportion of the retaining sleeve may be flared to form a flared portion92 of the second portion of the retaining sleeve as shown in FIG. 6,such as by using a tool T5648-12, for example. Optionally, in alternateembodiments, those skilled in the art will appreciate other tools may beused to flare the second portion of the retaining sleeve. Once thesecond portion of the retaining sleeve is flared, the second end orbottom end portion of the cylindrical shaft of the fastener is ready tobe flared, as shown in FIG. 6. A tool T2797-12 can be used to flare thesecond end or bottom end portion of the cylindrical shaft of thefastener to form a flared second end portion 94 of the cylindricalmember of the fastener, as shown in FIG. 7, so that the flared portionof the second end or bottom end portion of the cylindrical shaft of thefastener has an outer diameter 95 that is larger than the inner diameterof the prongs of the retaining sleeve, to retain the captive panelfastener within the retaining sleeve. In optional embodiments, thoseskilled in the art will appreciate other tools may be used to flare thesecond end or bottom end portion of the cylindrical shaft of thefastener. FIGS. 7 and 8 both illustrate a captive panel fastener/sleeveassembly where the second end or bottom end portion of the cylindricalshaft of the captive panel fastener has been flared. The retainingsleeve is typically positioned on a back side of the panel to preventthe fastener from sliding back out. The combination of the retainingsleeve and the flaring of the second end or bottom end portion of thecylindrical shaft of the fastener hold the captive panel fastener inplace in the panel.

Referring to FIGS. 10-20, in a second embodiment, the present inventionprovides for a captive panel fastener assembly 140 with multipleretaining elements including a captive panel fastener 142 having a head144 attached to a cylindrical member or shank 146, shown in FIGS. 10-13.The cylindrical member has an unthreaded first end or top end portion148, which connects to the head, a second end or bottom end portion 150,which is located opposite the first end or top end portion, and anexternally threaded portion 152 between the unthreaded first end or topend portion and the second end or bottom end portion. The cylindricalmember includes one or more pins 154 positioned internally within thecylindrical member near the second end or bottom end portion. The one ormore pins are internally positioned, are spring loaded and are designedto extend out through the cylindrical member. Further, a plurality oflongitudinally extending grooves or slots 156 run along the cylindricalmember between the first end or top end portion and the second end orbottom end portion. The longitudinally extending grooves preferably donot extend all the way to the extreme bottom end 160 of the second endor bottom end portion of the cylindrical member or shank, but insteadstop at a stop point 158 before reaching the outer or extreme bottom end160 of the second end or bottom end portion of the cylindrical member orshank.

The head of the captive panel fastener may include any type of drivingarrangement 162, such as a conventional slot, a Phillips, or Allen headrecess, or the like. FIG. 1 illustrates a top view of the head in theshape of a hexagon having a six-lobe recess 164. However, those skilledin the art will understand that a head of any shape and recessedconfiguration may be provided.

Referring now to FIG. 12, a cross section through the line 12-12 of FIG.11 is shown. FIG. 12 illustrates a different view of the longitudinallyextending grooves.

The captive panel fastener assembly also includes a retaining ring 166,illustrated shown in FIGS. 11 and 13-15. The retaining ring includes atleast two radially inwardly extending opposing prongs 168 that fit intothe longitudinally extending grooves of the cylindrical member of thefastener. The opposing prongs are formed to extend in the same plane asthe main body 169 of the retaining ring, and the opposing prongs areseparated by a first distance A shown in FIG. 14 that is slightly lessthan the distance B between the radially inner floors or bottoms 170 ofthe plurality of longitudinally extending grooves or slots along thecylindrical member, shown in FIG. 12. FIG. 13 illustrates a retainingring installed onto a captive panel fastener in which the assembly hasbeen installed into a panel 172, including a hole or bore 174 forinserting the captive panel fastener of the invention, or anotherfastener, such as a screw or bolt, for example.

FIG. 16 illustrates an installation tool 196 intended for use ininstalling the retaining ring over the second end portion of thecylindrical member of the captive panel fastener. The installation toolincludes a tool end portion 198 having a beveled portion 200 on one sideof the tool end portion, and a slot 202 on an opposing side of the toolend portion. A captive panel fastener is inserted into a panel as shownin FIG. 17. Then, one of the prongs of the retaining ring is insertedinto one of the longitudinally extending grooves. The installation toolis then positioned such that another one of the prongs of the retainingring that is not inserted in one of the longitudinally extending groovesis inside the tool's slot (as shown in FIG. 18). The installation toolthen stretches, or pulls, the retaining ring so that the prong may beinserted into the other longitudinally extending groove, thus securingthe retaining ring with the captive panel fastener. The captive panelfastener is then pulled through the panel and the pins positioned nearthe end of the cylinder portion are depressed within the panel, thusholding the fastener into place via a spring action of the pins.Further, the retaining ring is positioned on a back side of the panel toprevent the fastener from sliding back out. The combination of theretaining ring and the one or more pins hold the captive panel fastenerin place.

FIG. 19 illustrates a cross-sectional view of a portion of the fastenerin which the pin is extended outwardly. FIG. 20 illustrates across-sectional view of a portion of the fastener in which the pin isdepressed inwardly.

Referring to FIGS. 21-32, in a third embodiment, the present inventionprovides for a captive panel fastener assembly 240 with multipleretaining elements including a captive panel fastener 242 with multipleretaining functionality. Referring to FIGS. 21-24, the captive panelfastener includes a head 244 attached to a cylindrical member 246. Thecylindrical member (also called the shank) has an unthreaded first endor top end portion 248, which connects to the head, a second end orbottom end portion 250 which is located opposite the first end or topend portion, and an externally threaded portion 252 between theunthreaded first end or top end portion and the second end or bottom endportion. The cylindrical member includes one or more pins 254 positionedinternally within corresponding apertures 255 in the cylindrical membernear the second end or bottom end portion. The one or more pins areinternally positioned, are spring loaded, and are designed to extend outthrough the cylindrical member. A plurality of longitudinally extendinggrooves (or slots) 256 run along the cylindrical member between thefirst end or top end portion and the second end or bottom end portion.FIG. 23 illustrates a cross sectional view of the longitudinallyextending grooves. The head of the captive panel fastener may includeany type of driving arrangement 262, such as a conventional slot, aPhillips, or Allen head recess, or the like. FIG. 21 illustrates a topview of the head in the shape of a hexagon having a six-lobe recess 264.However, those skilled in the art will understand that a head of anyshape and recessed configuration may be provided.

The captive panel fastener assembly includes a retaining ring 266 asshown in FIGS. 25, 26, 31 and 32. The retaining ring includes at leasttwo radially inwardly extending, slightly flexible, flared opposingprongs 268 that fit into the longitudinally extending grooves of thecylindrical member of the fastener. In forming the retaining ring,initially these prongs are in the same plane as the main body 269 of theretaining ring, and the opposing prongs are separated by a firstdistance C shown in FIG. 31 that is slightly less than the distance Bbetween the radially inner surfaces, floors or bottoms 270 of theplurality of longitudinally extending grooves or slots along thecylindrical member, such as approximately 0.114 to 0.111 inches, forexample. As is illustrated in FIGS. 26 and 32, the prongs are preferablybent to flare in a direction outwardly from the plane of the main bodyof the retaining ring, so that the opposing prongs are separated by adistance A that is slightly less than the distance between the radiallyinner floors or bottoms of the plurality of longitudinally extendinggrooves or slots along the cylindrical member, and that is slightlygreater than the distance C, as is illustrated in FIG. 31. The flaredprongs function in a manner similar to leaf springs in that the flaredprongs give slightly and at the same time are biased to exert a pressureon the floors or bottoms of the plurality of longitudinally extendinggrooves or slots along the cylindrical member, to grip the fastener andresist movement of the retaining ring along the plurality oflongitudinally extending grooves or slots along the cylindrical member.The prongs are preferably bent to precisely apply a desired measure ofspring force against the plurality of longitudinally extending groovesor slots.

FIG. 24 illustrates a retaining ring installed onto a captive panelfastener in which the assembly has been installed into a panel 272. Thepanel includes a hole or bore 274 for inserting the captive panelfastener of the invention, or a screw or bolt, for example.

The retaining ring is mounted over the end of the captive panel fastenerwith the flared prongs positioned in the corresponding grooves or slotsof the cylindrical member. The captive panel fastener is pulled throughthe panel, and the pins near the end of the cylinder portion are pulledwithin the bore of the panel so that the pins are depressed within thebore of the panel to be biased in engagement with the inner surface ofthe bore of the panel, thus holding the fastener into place via a springaction of the pins. The retaining ring is positioned on a back side ofthe panel to prevent the fastener from sliding back out. The combinationof the retaining ring and the one or more pins hold the captive panelfastener in place.

It will be apparent from the foregoing that while particular forms ofthe invention have been illustrated and described, various modificationscan be made without departing from the spirit and scope of theinvention. Accordingly, it is not intended that the invention belimited, except as by the appended claims.

1. A captive panel fastener assembly to be installed in a bore of apanel, comprising: a fastener including a head attached to a cylindricalmember, said cylindrical member including a first end portion connectedto said head, a second end portion located opposite the first endportion, and an externally threaded portion between said first endportion and said second end portion; a plurality of longitudinallyextending grooves defined along an external surface of the cylindricalmember extending between said first end portion and said second endportion of said cylindrical member; a retaining ring mounted over saidcylindrical member, said retaining ring including at least two radiallyinwardly extending opposing prongs that fit into said plurality oflongitudinally extending grooves of the cylindrical member, wherein saidplurality of longitudinally extending grooves include radially innersurfaces separated by a first distance, and said inwardly extendingopposing prongs being separated by a second distance that is less thansaid first distance between said radially inner surfaces of saidplurality of longitudinally extending grooves; primary means forretaining said retaining ring on said cylindrical member; and secondarymeans for retaining said cylindrical member within the bore of thepanel.
 2. The captive panel fastener assembly of claim 1, wherein saidprimary means for retaining said retaining ring on said cylindricalmember comprises a stop point in said longitudinally extending groovesat or near an extreme end of said second end portion of said cylindricalmember.
 3. The captive panel fastener assembly of claim 1, wherein saidprimary means for retaining said retaining ring on said cylindricalmember comprises said at least two radially inwardly extending opposingprongs being slightly flexible and flared, and said at least tworadially inwardly extending opposing prongs being biased to grip saidplurality of longitudinally extending grooves and resist movement ofsaid retaining ring along said plurality of longitudinally extendinggrooves along the cylindrical member.
 4. The captive panel fastenerassembly of claim 1, wherein said secondary means for retaining saidcylindrical member within the bore of the panel comprises at least onespring loaded pin positioned internally within said cylindrical membernear the second end portion of said cylindrical member, said at leastone spring loaded pin extending externally through the cylindricalmember.
 5. The captive panel fastener assembly of claim 4, wherein saidat least one spring loaded pin comprises a plurality of spring loadedpins.
 6. A captive panel fastener assembly to be installed in a bore ofa panel, comprising: a fastener including a head attached to acylindrical member, said cylindrical member including a first endportion connected to said head, a second end portion located oppositethe first end portion, and an externally threaded portion between saidfirst end portion and said second end portion; at least one springloaded pin positioned internally within said cylindrical member near thesecond end portion of said cylindrical member, said at least one springloaded pin extending externally through the cylindrical member; aplurality of longitudinally extending grooves defined along an externalsurface of the cylindrical member extending between said first endportion and said second end portion of said cylindrical member; aretaining ring mounted over said cylindrical member, said retaining ringincluding at least two radially inwardly extending, slightly flexible,flared opposing prongs that fit into said plurality of longitudinallyextending grooves of the cylindrical member, said at least two radiallyinwardly extending, slightly flexible, flared opposing prongs beingbiased to grip said plurality of longitudinally extending grooves andresist movement of said retaining ring along said plurality oflongitudinally extending grooves along the cylindrical member.
 7. Thecaptive panel fastener assembly of claim 6, wherein said at least onespring loaded pin comprises a plurality of spring loaded pins.
 8. Acaptive panel fastener assembly to be installed in a bore of a panel,comprising: a fastener including a head attached to a cylindricalmember, said cylindrical member including a first end portion connectedto said head, a second end portion located opposite the first endportion, and an externally threaded portion between said first endportion and said second end portion; at least one spring loaded pinpositioned internally within said cylindrical member near the second endportion of said cylindrical member, said at least one spring loaded pinextending externally through the cylindrical member; a plurality oflongitudinally extending grooves defined along an external surface ofthe cylindrical member extending between said first end portion and saidsecond end portion of said cylindrical member, wherein saidlongitudinally extending grooves do not extend all the way to an extremeend of the second end or bottom end portion of said cylindrical member,but instead stop at a stop point before reaching the extreme end of thesecond end or bottom end portion of said cylindrical member; and aretaining ring mounted over said cylindrical member, said retaining ringincluding at least two radially inwardly extending opposing prongs thatfit into said plurality of longitudinally extending grooves of thecylindrical member, said plurality of longitudinally extending grooveshaving radially inner surfaces separated by a first distance, and saidinwardly extending opposing prongs being separated by a second distancethat is less than said first distance between said radially innersurfaces of said plurality of longitudinally extending grooves.